No full throttle

My throttle lever seems to do nothing more between 3/4 and full throttle. So it reaches a maximum of about 7100RPM (and about 37MPH) doesn't matter if I'm 3/4 or full open. It's a 2012 Challenger 180 and I'm told it is not by cable... so I wonder if it would be the throttle lever itself? Any hints where to look?